1. Field of the Invention
This invention relates to optical and wireless transmission of digital data.
2. Description of the Related Art
Some schemes transmit digital data encoded as a modulation on an optical subcarrier. An optical subcarrier is a periodic amplitude modulation on a substantially monochromatic optical carrier. An unmodulated optical subcarrier may be produced by amplitude modulating an output from a continuous wave laser or by interfering light from two continuous wave lasers with nearby wavelengths. The unmodulated optical subcarrier has wavelength that is much longer than the wavelength of the underlying optical carrier.
Present methods and systems use complex modulators and modulation schemes to transmit data via a modulation of an optical subcarrier. Improved methods and systems for transmitting data on optical subcarriers are desirable.